Eucalyptus is an evergreen tree that is native to Australia. It belongs to the family Myrtaceae. It grows up to a height of 25 to 50 meters with around 2-meter diameter. However, there will be differences in the heights of the plant depending upon the species.
The essential oil of eucalyptus leaves is used for its medicinal properties. The plant is also known as a gum tree and Nilagiri tree.
Uses: The essential oil is a rubefacient and used for many purposes.
- It helps in reducing cold and fever.
- Leaves of eucalyptus are used in the preparation of air fresheners.
- Eucalyptus is useful in the preparation of various dental products and antiseptics etc.
- Ointments prepared from eucalyptus are used to treat minor aches and pains.
- The timber of eucalyptus is used for various purposes.
- Used in the treatment of sinus and allergies.
- Oil of eucalyptus gives temporary relief from the muscle and joint pains when they are applied.
- In some parts of the world, its oil is used as a bug repellent.
Clones and varieties:
FRI- 4, FRI – 6,271, 3, 288, 413, 7, E. globules and E. citriodora
Its cultivation is possible under a wide range of soil conditions including those with low fertility. However, well-drained, loamy soils with rich in organic matter are most suitable for eucalyptus cultivation. Avoid eucalyptus cultivation under saline or alkaline soils that affect the growth and development of the plant. Optimum pH for eucalyptus cultivation is 6.0-7.5.
It can be grown under tropical to temperate climatic conditions. Suitable temperature for cultivation is 0 – 40 ̊ C. Average rainfall required for eucalyptus cultivation is 4400 – 1250 mm. It can tolerate drought conditions. Hence, eucalyptus can be cultivated under wastelands and drought-prone areas. However, severe drought and frost are detrimental to the eucalyptus cultivation.
Eucalyptus propagation is done by either by seed or vegetative propagation. However, mostly it is propagated by seeds. Seeds are sown in poly bags in the nursery. Seeds will germinate within 10-15 days after sowing. These seedlings will ready for transplanting when they are 2- 3 months old and attain a 5 – 6 leaf stage. The root system of eucalyptus is susceptible. Hence, care should be taken during transplantation.
Remove all weeds and stubbles before plowing the land. Perform around 1 – 2 are plowings to get a fine tilth of the soil. The addition of farmyard manure before plowing is beneficial.
Time of sowing:
June – October or commencement of monsoon (southwest) is said to be an ideal time of planting of eucalyptus.
Spacing followed in eucalyptus plantation is either 2 m × 2 m which can accommodate around 1200 plants per acre or 1.5 × 1.5 m it can accommodate 1690 plants per acre.
As eucalyptus does not have spreading canopy we can grow various crops in the same filed in between.
This is called as intercropping and can be done in the early 2 – 3 years of growth.
Apply farmyard manure yearly. Along with farmyard manure apply chemical fertilizers also as eucalyptus is highly responsive to the fertilizer application. Fertilizer applications should be done at the end of the monsoon.
First-year 30: 20: 20 grams of Nitrogen, phosphorous and potash per tree.
Second-year 60: 40: 40 grams of Nitrogen, phosphorous and potash per tree.
Third-year 90: 60: 60 grams of Nitrogen, phosphorous and potash per tree.
Fourth-year 120: 80: 80 grams of Nitrogen, phosphorous and potash per tree.
Fifth-year 150: 100: 100 grams of Nitrogen, phosphorous and potash per tree.
Apply the recommended dose of nitrogen in 3 split doses.
Removing overpopulated, weak, and diseased plants, from the field is called thinning. In eucalyptus thinning is practiced after one year. Remove all diseases, excessive and plants with weak growth.
Fill the gaps of dead plants to maintain an optimum population in the field. It should be done up to 2 years.
Provide staking to the young growing plants with help bamboo sticks etc.to protect the plants from wind damage etc.
There no problem with the weeds with later stages of growth. But it is important to keep the field in the early stages. 2- 3 hand weedings are necessary to control weeds in the early stages. Spray herbicides if necessary.
Provide irrigation immediately after transplanting. Eucalyptus can tolerate drought conditions to some extent. In monsoon, if the rainfall is good, you need not provide irrigation. In the case of monsoon failure providing protective irrigations will be necessary.
Removals excessive growth of the plants like outgrown twigs, dried leaves, and diseased plant parts, etc. is called pruning. Pruning ensures better growth and development of the plant. In eucalyptus, pruning is carried out at the end of the second year.
Pest and diseases:
Termites: Termites cause great damage to the plants.
Management: Spraying of Nimbicides at 2 grams per liter of water immediately after termite attack with the help of knapsack sprayer will control termites effectively.
Use resistant verities
Collection and destruction of affected plant parts.
Application of Bordeaux mixture controls canker effectively.
Generally, harvesting is done at the end of every fourth year by coppicing 5 cm above the stem. Leaves are collected at every 6 – 12 months intervals to extract the essential oil through steam distillation. Leaves are dried for three days before subjecting to the steam distillation. Best time for harvesting the leaves in March to May as leaves contain a high content of essential oil at this time. In some parts of the country collection of the leaves was done twice per year. On average leaves yield about 1 % oil.
The average expected yield is 80- 100 MT per hectare in 8 years. There might be differences in yield depending upon various factors like variety used, the package of practices adopted, etc.